libbb: make bb_common_bufsiz1 1 kbyte, add capability to use bss tail for it

The config item is FEATURE_USE_BSS_TAIL. When it is off (default):

function                                             old     new   delta
read_config                                          210     228     +18
doCommands                                          2279    2294     +15
ipneigh_list_or_flush                                763     772      +9
ipaddr_list_or_flush                                1256    1261      +5
display_process_list                                1301    1306      +5
conspy_main                                         1378    1383      +5
do_lzo_compress                                      352     355      +3
do_lzo_decompress                                    565     567      +2
push                                                  46      44      -2
inetd_main                                          2136    2134      -2
uevent_main                                          421     418      -3
addLines                                              97      92      -5
bb_common_bufsiz1                                   8193    1024   -7169
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 8/5 up/down: 62/-7181)        Total: -7119 bytes
   text	   data	    bss	    dec	    hex	filename
 829850	   4086	   9080	 843016	  cdd08	busybox_old
 829901	   4086	   1904	 835891	  cc133	busybox_unstripped

FEATURE_USE_BSS_TAIL=y:

read_config                                          210     228     +18
doCommands                                          2279    2294     +15
ipneigh_list_or_flush                                763     772      +9
ipaddr_list_or_flush                                1256    1261      +5
display_process_list                                1301    1306      +5
conspy_main                                         1378    1383      +5
do_lzo_compress                                      352     355      +3
do_lzo_decompress                                    565     567      +2
inetd_main                                          2136    2134      -2
bb_common_bufsiz1                                   8193       -   -8193
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 8/1 up/down: 62/-8195)        Total: -8133 bytes
   text	   data	    bss	    dec	    hex	filename
 829850	   4086	   9080	 843016	  cdd08	busybox_old
 829911	   4086	    880	 834877	  cbd3d	busybox_unstripped

FIXME: setup_common_bufsiz() calls are missing.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

Makefile

@@ -610,7 +610,8 @@ quiet_cmd_busybox__ ?= LINK    $@
       "$(LDFLAGS) $(EXTRA_LDFLAGS)" \
       "$(core-y)" \
       "$(libs-y)" \
-      "$(LDLIBS)"
+      "$(LDLIBS)" \
+      && $(srctree)/scripts/generate_BUFSIZ.sh include/common_bufsiz.h
 
 # Generate System.map
 quiet_cmd_sysmap = SYSMAP
@@ -844,12 +845,15 @@ export CPPFLAGS_busybox.lds += -P -C -U$(ARCH)
 # 	Split autoconf.h into include/linux/config/*
 quiet_cmd_gen_bbconfigopts = GEN     include/bbconfigopts.h
       cmd_gen_bbconfigopts = $(srctree)/scripts/mkconfigs include/bbconfigopts.h include/bbconfigopts_bz2.h
+quiet_cmd_gen_common_bufsiz = GEN     include/common_bufsiz.h
+      cmd_gen_common_bufsiz = $(srctree)/scripts/generate_BUFSIZ.sh include/common_bufsiz.h
 quiet_cmd_split_autoconf   = SPLIT   include/autoconf.h -> include/config/*
       cmd_split_autoconf   = scripts/basic/split-include include/autoconf.h include/config
 #bbox# piggybacked generation of few .h files
 include/config/MARKER: scripts/basic/split-include include/autoconf.h
 	$(call cmd,split_autoconf)
 	$(call cmd,gen_bbconfigopts)
+	$(call cmd,gen_common_bufsiz)
 	@touch $@
 
 # Generate some files
@@ -965,6 +969,7 @@ CLEAN_FILES +=	busybox busybox_unstripped* busybox.links \
 MRPROPER_DIRS  += include/config include2
 MRPROPER_FILES += .config .config.old include/asm .version .old_version \
 		  include/NUM_APPLETS.h \
+		  include/common_bufsiz.h \
 		  include/autoconf.h \
 		  include/bbconfigopts.h \
 		  include/bbconfigopts_bz2.h \

archival/cpio.c

@@ -11,6 +11,7 @@
  * Only supports new ASCII and CRC formats
  */
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "bb_archive.h"
 
 //config:config CPIO
@@ -170,7 +171,7 @@ enum {
 struct globals {
 	struct bb_uidgid_t owner_ugid;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 void BUG_cpio_globals_too_big(void);
 #define INIT_G() do { \
 	G.owner_ugid.uid = -1L; \

archival/lzop.c

@@ -71,6 +71,7 @@
 //usage:     "\n	-F	Don't store or verify checksum"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "bb_archive.h"
 #include "liblzo_interface.h"
 
@@ -443,7 +444,7 @@ struct globals {
 	chksum_t chksum_in;
 	chksum_t chksum_out;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 //#define G (*ptr_to_globals)
 //#define INIT_G() do {

archival/rpm.c

@@ -29,6 +29,7 @@
 //usage:     "\n	-qpc	List config files"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "bb_archive.h"
 #include "rpm.h"
 
@@ -93,7 +94,7 @@ struct globals {
 	rpm_index **mytags;
 	int tagcount;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 static void extract_cpio(int fd, const char *source_rpm)

archival/tar.c

@@ -146,6 +146,7 @@
 
 #include <fnmatch.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "bb_archive.h"
 /* FIXME: Stop using this non-standard feature */
 #ifndef FNM_LEADING_DIR

console-tools/dumpkmap.c

@@ -18,6 +18,7 @@
 //usage:       "$ dumpkmap > keymap\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* From <linux/kd.h> */
 struct kbentry {

console-tools/resize.c

@@ -14,10 +14,11 @@
 //usage:       "Resize the screen"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #define ESC "\033"
 
-#define old_termios_p ((struct termios*)&bb_common_bufsiz1)
+#define old_termios_p ((struct termios*)bb_common_bufsiz1)
 
 static void
 onintr(int sig UNUSED_PARAM)

coreutils/catv.c

@@ -19,6 +19,7 @@
 //usage:     "\n	-v	Don't use ^x or M-x escapes"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #define CATV_OPT_e (1<<0)
 #define CATV_OPT_t (1<<1)

coreutils/cksum.c

@@ -13,6 +13,7 @@
 //usage:       "Calculate the CRC32 checksums of FILES"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* This is a NOEXEC applet. Be very careful! */
 
@@ -43,7 +44,8 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
 		length = 0;
 
 #define        read_buf bb_common_bufsiz1
-		while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
+#define sizeof_read_buf COMMON_BUFSIZE
+		while ((bytes_read = safe_read(fd, read_buf, sizeof_read_buf)) > 0) {
 			length += bytes_read;
 			crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table);
 		}

coreutils/date.c

@@ -138,6 +138,7 @@
 //usage:       "Wed Apr 12 18:52:41 MDT 2000\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_FEATURE_DATE_NANO
 # include <sys/syscall.h>
 #endif
@@ -368,6 +369,7 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 #endif
 
 #define        date_buf bb_common_bufsiz1
+#define sizeof_date_buf COMMON_BUFSIZE
 	if (*fmt_dt2str == '\0') {
 		/* With no format string, just print a blank line */
 		date_buf[0] = '\0';
@@ -377,7 +379,7 @@ int date_main(int argc UNUSED_PARAM, char **argv)
 			fmt_dt2str = (char*)"%Y.%m.%d-%H:%M:%S";
 		}
 		/* Generate output string */
-		strftime(date_buf, sizeof(date_buf), fmt_dt2str, &tm_time);
+		strftime(date_buf, sizeof_date_buf, fmt_dt2str, &tm_time);
 	}
 	puts(date_buf);
 

coreutils/dd.c

@@ -91,6 +91,7 @@
 //usage:       "4+0 records out\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* This is a NOEXEC applet. Be very careful! */
 
@@ -108,7 +109,7 @@ struct globals {
 #endif
 	int flags;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	/* we have to zero it out because of NOEXEC */ \
 	memset(&G, 0, sizeof(G)); \

coreutils/du.c

@@ -58,6 +58,7 @@
 //usage:       "2417    .\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 enum {
 	OPT_a_files_too    = (1 << 0),
@@ -85,7 +86,7 @@ struct globals {
 	int du_depth;
 	dev_t dir_dev;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 

coreutils/expr.c

@@ -61,6 +61,7 @@
 //usage:       "of characters matched or 0."
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "xregex.h"
 
 #if ENABLE_EXPR_MATH_SUPPORT_64
@@ -99,7 +100,7 @@ typedef struct valinfo VALUE;
 struct globals {
 	char **args;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 /* forward declarations */

coreutils/ls.c

@@ -93,6 +93,7 @@
 //usage:	)
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "unicode.h"
 
 
@@ -365,7 +366,7 @@ struct globals {
 	time_t current_time_t;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	/* we have to zero it out because of NOEXEC */ \
 	memset(&G, 0, sizeof(G)); \

coreutils/od_bloaty.c

@@ -20,6 +20,7 @@
 
 
 /* #include "libbb.h" - done in od.c */
+#include "common_bufsiz.h"
 #define assert(a) ((void)0)
 
 
@@ -214,7 +215,7 @@ struct globals {
 #if !ENABLE_LONG_OPTS
 enum { G_pseudo_offset = 0 };
 #endif
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 	G.bytes_per_block = 32; \

coreutils/split.c

@@ -22,6 +22,7 @@
 //usage:       "$ cat TODO | split -a 2 -l 2 TODO_\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if ENABLE_FEATURE_SPLIT_FANCY
 static const struct suffix_mult split_suffixes[] = {

coreutils/stat.c

@@ -103,6 +103,7 @@
 //usage:	)
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 enum {
 	OPT_TERSE       = (1 << 0),
@@ -158,8 +159,9 @@ static const char *human_time(time_t t)
 
 	/*static char buf[sizeof("YYYY-MM-DD HH:MM:SS.000000000")] ALIGN1;*/
 #define        buf bb_common_bufsiz1
+#define sizeof_buf COMMON_BUFSIZE
 
-	strcpy(strftime_YYYYMMDDHHMMSS(buf, sizeof(buf), &t), ".000000000");
+	strcpy(strftime_YYYYMMDDHHMMSS(buf, sizeof_buf, &t), ".000000000");
 	return buf;
 #undef buf
 }

coreutils/stty.c

@@ -32,6 +32,7 @@
 //usage:     "\n	[SETTING]	See manpage"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #ifndef _POSIX_VDISABLE
 # define _POSIX_VDISABLE ((unsigned char) 0)
@@ -775,7 +776,7 @@ struct globals {
 	unsigned current_col;
 	char buf[10];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.device_name = bb_msg_standard_input; \
 	G.max_col = 80; \

coreutils/sum.c

@@ -21,6 +21,7 @@
 //usage:     "\n	-s	Use System V sum algorithm (512byte blocks)"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 enum { SUM_BSD, PRINT_NAME, SUM_SYSV };
 
@@ -41,7 +42,7 @@ static unsigned sum_file(const char *file, unsigned type)
 		return 0;
 
 	while (1) {
-		size_t bytes_read = safe_read(fd, buf, BUFSIZ);
+		size_t bytes_read = safe_read(fd, buf, COMMON_BUFSIZE);
 
 		if ((ssize_t)bytes_read <= 0) {
 			r = (fd && close(fd) != 0);

coreutils/tail.c

@@ -49,12 +49,13 @@
 //usage:       "nameserver 10.0.0.1\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 struct globals {
 	bool from_top;
 	bool exitcode;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 static void tail_xprint_header(const char *fmt, const char *filename)

coreutils/tee.c

@@ -23,6 +23,7 @@
 //usage:       "Hello\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 int tee_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int tee_main(int argc, char **argv)
@@ -37,6 +38,7 @@ int tee_main(int argc, char **argv)
 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
 	ssize_t c;
 # define        buf bb_common_bufsiz1
+# define sizeof_buf COMMON_BUFSIZE
 #else
 	int c;
 #endif
@@ -79,7 +81,7 @@ int tee_main(int argc, char **argv)
 	/* names[0] will be filled later */
 
 #if ENABLE_FEATURE_TEE_USE_BLOCK_IO
-	while ((c = safe_read(STDIN_FILENO, buf, sizeof(buf))) > 0) {
+	while ((c = safe_read(STDIN_FILENO, buf, sizeof_buf)) > 0) {
 		fp = files;
 		do
 			fwrite(buf, 1, c, *fp);

debianutils/run_parts.c

@@ -89,13 +89,14 @@
 //usage:       "+ shutdown -h +4m"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 struct globals {
 	char **names;
 	int    cur;
 	char  *cmd[2 /* using 1 provokes compiler warning */];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define names (G.names)
 #define cur   (G.cur  )
 #define cmd   (G.cmd  )

debianutils/start_stop_daemon.c

@@ -153,6 +153,7 @@ Misc options:
 /* Override ENABLE_FEATURE_PIDFILE */
 #define WANT_PIDFILE 1
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 struct pid_list {
 	struct pid_list *next;
@@ -191,7 +192,7 @@ struct globals {
 	int user_id;
 	smallint signal_nr;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define userspec          (G.userspec            )
 #define cmdname           (G.cmdname             )
 #define execname          (G.execname            )

e2fsprogs/fsck.c

@@ -60,6 +60,7 @@
 //usage:     "\n	-t TYPE	List of filesystem types to check"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* "progress indicator" code is somewhat buggy and ext[23] specific.
  * We should be filesystem agnostic. IOW: there should be a well-defined
@@ -169,7 +170,7 @@ struct globals {
 	struct fs_info *filesys_last;
 	struct fsck_instance *instance_list;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 } while (0)

editors/diff.c

@@ -125,6 +125,7 @@
 //usage:     "\n	-w	Ignore all whitespace"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if 0
 # define dbg_error_msg(...) bb_error_msg(__VA_ARGS__)

editors/ed.c

@@ -23,6 +23,7 @@
 //usage:#define ed_full_usage ""
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 typedef struct LINE {
 	struct LINE *next;
@@ -33,10 +34,11 @@ typedef struct LINE {
 
 
 #define        searchString bb_common_bufsiz1
+#define sizeof_searchString COMMON_BUFSIZE
 
 enum {
-	USERSIZE = sizeof(searchString) > 1024 ? 1024
+	USERSIZE = sizeof_searchString > 1024 ? 1024
-	         : sizeof(searchString) - 1, /* max line length typed in by user */
+	         : sizeof_searchString - 1, /* max line length typed in by user */
 	INITBUF_SIZE = 1024, /* initial buffer size */
 };
 

editors/sed.c

@@ -86,6 +86,7 @@
 //usage:       "bar\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "xregex.h"
 
 #if 0
@@ -161,7 +162,7 @@ struct globals {
 		int len;    /* Space allocated */
 	} pipeline;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 	G.sed_cmd_tail = &G.sed_cmd_head; \

findutils/find.c

@@ -342,6 +342,7 @@
 
 #include <fnmatch.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_FEATURE_FIND_REGEX
 # include "xregex.h"
 #endif
@@ -421,7 +422,7 @@ struct globals {
 	recurse_flags_t recurse_flags;
 	IF_FEATURE_FIND_EXEC_PLUS(unsigned max_argv_len;)
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 	/* we have to zero it out because of NOEXEC */ \

findutils/grep.c

@@ -58,6 +58,7 @@
 //config:	  Print the specified number of context lines (-C).
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "xregex.h"
 
 
@@ -201,7 +202,7 @@ struct globals {
 	llist_t *pattern_head;   /* growable list of patterns to match */
 	const char *cur_file;    /* the current file we are reading */
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 } while (0)

findutils/xargs.c

@@ -66,6 +66,7 @@
 //kbuild:lib-$(CONFIG_XARGS) += xargs.o
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* This is a NOEXEC applet. Be very careful! */
 
@@ -100,7 +101,7 @@ struct globals {
 	const char *eof_str;
 	int idx;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.eof_str = NULL; /* need to clear by hand because we are NOEXEC applet */ \
 	IF_FEATURE_XARGS_SUPPORT_REPL_STR(G.repl_str = "{}";) \

include/libbb.h

@@ -1827,10 +1827,6 @@ extern const char bb_PATH_root_path[] ALIGN1; /* "PATH=/sbin:/usr/sbin:/bin:/usr
 extern const int const_int_0;
 //extern const int const_int_1;
 
-
-/* Providing hard guarantee on minimum size (think of BUFSIZ == 128) */
-enum { COMMON_BUFSIZE = (BUFSIZ >= 256*sizeof(void*) ? BUFSIZ+1 : 256*sizeof(void*)) };
-extern char bb_common_bufsiz1[COMMON_BUFSIZE];
 /* This struct is deliberately not defined. */
 /* See docs/keep_data_small.txt */
 struct globals;

init/bootchartd.c

@@ -47,6 +47,7 @@
 //config:	  and /etc/bootchartd.conf files.
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 /* After libbb.h, since it needs sys/types.h on some systems */
 #include <sys/utsname.h>
 
@@ -115,7 +116,7 @@
 struct globals {
 	char jiffy_line[COMMON_BUFSIZE];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 static void dump_file(FILE *fp, const char *filename)

libbb/common_bufsiz.c

@@ -0,0 +1,74 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 2016 Denys Vlasenko
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+//config:config FEATURE_USE_BSS_TAIL
+//config:	bool "Use the end of BSS page"
+//config:	default n
+//config:	help
+//config:	  Attempt to reclaim a small unused part of BSS.
+//config:
+//config:	  Executables have the following parts:
+//config:	  = read-only executable code and constants, also known as "text"
+//config:	  = read-write data
+//config:	  = non-initialized (zeroed on demand) data, also known as "bss"
+//config:
+//config:	  At link time, "text" is padded to a full page. At runtime, all "text"
+//config:	  pages are mapped RO and executable.
+//config:	  "Data" starts on the next page boundary, but is not padded
+//config:	  to a full page at the end. "Bss" starts wherever "data" ends.
+//config:	  At runtime, "data" pages are mapped RW and they are file-backed
+//config:	  (this includes a small portion of "bss" which may live in the last
+//config:	  partial page of "data").
+//config:	  Pages which are fully in "bss" are mapped to anonymous memory.
+//config:
+//config:	  "Bss" end is usually not page-aligned. There is an unused space
+//config:	  in the last page. Linker marks its start with the "_end" symbol.
+//config:
+//config:	  This option will attempt to use that space for bb_common_bufsiz1[]
+//config:	  array. If it fits after _end, it will be used, and COMMON_BUFSIZE
+//config:	  will be enlarged from its guaranteed minimum size of 1 kbyte.
+//config:	  This may require recompilation a second time, since value of _end
+//config:	  is known only after final link.
+//config:
+//config:	  If you are getting a build error like this:
+//config:	        appletlib.c:(.text.main+0xd): undefined reference to '_end'
+//config:	  disable this option.
+
+//kbuild:lib-y += common_bufsiz.o
+
+#include "libbb.h"
+#include "common_bufsiz.h"
+
+#if !ENABLE_FEATURE_USE_BSS_TAIL
+
+/* We use it for "global" data via *(struct global*)bb_common_bufsiz1.
+ * Since gcc insists on aligning struct global's members, it would be a pity
+ * (and an alignment fault on some CPUs) to mess it up. */
+char bb_common_bufsiz1[COMMON_BUFSIZE] ALIGNED(sizeof(long long));
+
+#else
+
+# ifndef setup_common_bufsiz
+/*
+ * It is not a "((void)0)" macro. It means we have to provide this function.
+ */
+char* bb_common_bufsiz1;
+char* setup_common_bufsiz(void)
+{
+	if (!bb_common_bufsiz1)
+		bb_common_bufsiz1 = xzalloc(COMMON_BUFSIZE);
+	return bb_common_bufsiz1;
+}
+# else
+#  ifndef bb_common_bufsiz1
+   /* bb_common_bufsiz1[] is not aliased to _end[] */
+char bb_common_bufsiz1[COMMON_BUFSIZE] ALIGNED(sizeof(long long));
+#  endif
+# endif
+
+#endif

libbb/messages.c

@@ -59,8 +59,3 @@ const char bb_path_wtmp_file[] ALIGN1 =
 #  error unknown path to wtmp file
 # endif
 #endif
-
-/* We use it for "global" data via *(struct global*)&bb_common_bufsiz1.
- * Since gcc insists on aligning struct global's members, it would be a pity
- * (and an alignment fault on some CPUs) to mess it up. */
-char bb_common_bufsiz1[COMMON_BUFSIZE] ALIGNED(sizeof(long long));

loginutils/login.c

@@ -62,6 +62,7 @@
 //usage:     "\n	-p	Preserve environment"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 #include <sys/resource.h>
 
@@ -138,7 +139,7 @@ enum {
 struct globals {
 	struct termios tty_attrs;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 

miscutils/chat.c

@@ -17,6 +17,7 @@
 //usage:       "chat '' ATZ OK ATD123456 CONNECT '' ogin: pppuser word: ppppass '~'"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 // default timeout: 45 sec
 #define DEFAULT_CHAT_TIMEOUT 45*1000

miscutils/conspy.c

@@ -42,6 +42,7 @@
 //usage:     "\n	-y LINE	Starting line"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <sys/kd.h>
 
 #define ESC "\033"
@@ -364,6 +365,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
 {
 	char tty_name[sizeof(DEV_TTY "NN")];
 #define        keybuf bb_common_bufsiz1
+#define sizeof_keybuf COMMON_BUFSIZE
 	struct termios termbuf;
 	unsigned opts;
 	unsigned ttynum;
@@ -513,7 +515,7 @@ int conspy_main(int argc UNUSED_PARAM, char **argv)
 		default:
 			// Read the keys pressed
 			k = keybuf + G.key_count;
-			bytes_read = read(G.kbd_fd, k, sizeof(keybuf) - G.key_count);
+			bytes_read = read(G.kbd_fd, k, sizeof_keybuf - G.key_count);
 			if (bytes_read < 0)
 				goto abort;
 

miscutils/crond.c

@@ -60,6 +60,7 @@
 //usage:     "\n	-c DIR	Cron dir. Default:"CONFIG_FEATURE_CROND_DIR"/crontabs"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 
 /* glibc frees previous setenv'ed value when we do next setenv()
@@ -140,7 +141,7 @@ struct globals {
 	char *env_var_logname;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.log_level = 8; \
 	G.crontab_dir_name = CRONTABS; \

miscutils/dc.c

@@ -4,6 +4,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <math.h>
 
 //usage:#define dc_trivial_usage
@@ -47,7 +48,7 @@ struct globals {
 	double stack[1];
 } FIX_ALIASING;
 enum { STACK_SIZE = (COMMON_BUFSIZE - offsetof(struct globals, stack)) / sizeof(double) };
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define pointer   (G.pointer   )
 #define base      (G.base      )
 #define stack     (G.stack     )

miscutils/fbsplash.c

@@ -34,6 +34,7 @@
 //usage:     "\n			commands: 'NN' (% for progress bar) or 'exit'"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <linux/fb.h>
 
 /* If you want logging messages on /tmp/fbsplash.log... */
@@ -373,10 +374,11 @@ static void fb_drawimage(void)
 	 *   in pure binary by 1 or 2 bytes. (we support only 1 byte)
 	 */
 #define        concat_buf bb_common_bufsiz1
+#define sizeof_concat_buf COMMON_BUFSIZE
 	read_ptr = concat_buf;
 	while (1) {
 		int w, h, max_color_val;
-		int rem = concat_buf + sizeof(concat_buf) - read_ptr;
+		int rem = concat_buf + sizeof_concat_buf - read_ptr;
 		if (rem < 2
 		 || fgets(read_ptr, rem, theme_file) == NULL
 		) {

miscutils/hdparm.c

@@ -63,6 +63,7 @@
 //usage:     "\n	-z	Reread partition table"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 /* must be _after_ libbb.h: */
 #include <linux/hdreg.h>
 #include <sys/mount.h>
@@ -367,7 +368,7 @@ struct globals {
 	unsigned char flushcache[4] = { WIN_FLUSHCACHE, 0, 0, 0 };
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define get_identity       (G.get_identity           )
 #define get_geom           (G.get_geom               )
 #define do_flush           (G.do_flush               )

miscutils/i2c_tools.c

@@ -60,6 +60,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #include <linux/i2c.h>
 #include <linux/i2c-dev.h>

miscutils/inotifyd.c

@@ -56,6 +56,7 @@
 //usage:     "\nWhen x event happens for all FILEs, inotifyd exits."
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <sys/inotify.h>
 
 static const char mask_names[] ALIGN1 =
@@ -163,7 +164,8 @@ int inotifyd_main(int argc, char **argv)
 		// (NB: len must be int, not ssize_t or long!)
 		xioctl(pfd.fd, FIONREAD, &len);
 #define        eventbuf bb_common_bufsiz1
-		ie = buf = (len <= sizeof(eventbuf)) ? eventbuf : xmalloc(len);
+#define sizeof_eventbuf COMMON_BUFSIZE
+		ie = buf = (len <= sizeof_eventbuf) ? eventbuf : xmalloc(len);
 		len = full_read(pfd.fd, buf, len);
 		// process events. N.B. events may vary in length
 		while (len > 0) {

miscutils/less.c

@@ -127,6 +127,7 @@
 #include <sched.h>  /* sched_yield() */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_FEATURE_LESS_REGEXP
 #include "xregex.h"
 #endif
@@ -440,6 +441,7 @@ static int at_end(void)
 static void read_lines(void)
 {
 #define        readbuf bb_common_bufsiz1
+#define sizeof_readbuf COMMON_BUFSIZE
 	char *current_line, *p;
 	int w = width;
 	char last_terminated = terminated;
@@ -480,7 +482,7 @@ static void read_lines(void)
 					time_t t;
 
 					errno = 0;
-					eof_error = safe_read(STDIN_FILENO, readbuf, sizeof(readbuf));
+					eof_error = safe_read(STDIN_FILENO, readbuf, sizeof_readbuf);
 					if (errno != EAGAIN)
 						break;
 					t = time(NULL);

miscutils/microcom.c

@@ -19,6 +19,7 @@
 //usage:     "\n	-X	Disable special meaning of NUL and Ctrl-X from stdin"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 // set raw tty mode
 static void xget1(int fd, struct termios *t, struct termios *oldt)
@@ -156,9 +157,10 @@ skip_write: ;
 		}
 		if (pfd[0].revents) {
 #define        iobuf bb_common_bufsiz1
+#define sizeof_iobuf COMMON_BUFSIZE
 			ssize_t len;
 			// read from device -> write to stdout
-			len = safe_read(sfd, iobuf, sizeof(iobuf));
+			len = safe_read(sfd, iobuf, sizeof_iobuf);
 			if (len > 0)
 				full_write(STDOUT_FILENO, iobuf, len);
 			else {

networking/arp.c

@@ -32,6 +32,7 @@
 //usage:       "\n	-H HWTYPE	Hardware address type"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "inet_common.h"
 
 #include <arpa/inet.h>
@@ -69,7 +70,7 @@ struct globals {
 	const char *device;      /* current device */
 	smallint hw_set;         /* flag if hw-type was set (-H) */
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define ap         (G.ap        )
 #define hw         (G.hw        )
 #define device     (G.device    )

networking/arping.c

@@ -28,6 +28,7 @@
 #include <netpacket/packet.h>
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* We don't expect to see 1000+ seconds delay, unsigned is enough */
 #define MONOTONIC_US() ((unsigned)monotonic_us())
@@ -60,7 +61,7 @@ struct globals {
 	unsigned brd_recv;
 	unsigned req_recv;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define src        (G.src       )
 #define dst        (G.dst       )
 #define me         (G.me        )

networking/ftpd.c

@@ -29,6 +29,7 @@
 //usage:     "\n	DIR	Change root to this directory"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 #include <netinet/tcp.h>
 
@@ -123,7 +124,7 @@ struct globals {
 	char msg_ok [(sizeof("NNN " MSG_OK ) + 3) & 0xfffc];
 	char msg_err[(sizeof("NNN " MSG_ERR) + 3) & 0xfffc];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	/* Moved to main */ \
 	/*strcpy(G.msg_ok  + 4, MSG_OK );*/ \

networking/ftpgetput.c

@@ -50,6 +50,7 @@
 //usage:	)
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 struct globals {
 	const char *user;
@@ -60,7 +61,7 @@ struct globals {
 	int do_continue;
 	char buf[4]; /* actually [BUFSZ] */
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 enum { BUFSZ = COMMON_BUFSIZE - offsetof(struct globals, buf) };
 #define user           (G.user          )
 #define password       (G.password      )

networking/httpd.c

@@ -125,6 +125,7 @@
 //usage:     "\n	-d STRING	URL decode STRING"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_PAM
 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 # undef setlocale
@@ -308,6 +309,7 @@ struct globals {
 #endif
 	char *iobuf;            /* [IOBUF_SIZE] */
 #define        hdr_buf bb_common_bufsiz1
+#define sizeof_hdr_buf COMMON_BUFSIZE
 	char *hdr_ptr;
 	int hdr_cnt;
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
@@ -1066,7 +1068,7 @@ static int get_line(void)
 	alarm(HEADER_READ_TIMEOUT);
 	while (1) {
 		if (hdr_cnt <= 0) {
-			hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
+			hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
 			if (hdr_cnt <= 0)
 				break;
 			hdr_ptr = hdr_buf;
@@ -1191,9 +1193,9 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
 			/* We expect data, prev data portion is eaten by CGI
 			 * and there *is* data to read from the peer
 			 * (POSTDATA) */
-			//count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
+			//count = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
 			//count = safe_read(STDIN_FILENO, hdr_buf, count);
-			count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
+			count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
 			if (count > 0) {
 				hdr_cnt = count;
 				hdr_ptr = hdr_buf;

networking/ifupdown.c

@@ -44,6 +44,7 @@
 //usage:     "\n	-f	Force de/configuration"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 /* After libbb.h, since it needs sys/types.h on some systems */
 #include <sys/utsname.h>
 #include <fnmatch.h>
@@ -129,7 +130,7 @@ struct globals {
 	const char *startup_PATH;
 	char *shell;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 

networking/inetd.c

@@ -170,6 +170,7 @@
 #include <sys/un.h>
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if ENABLE_FEATURE_INETD_RPC
 # if defined(__UCLIBC__) && ! defined(__UCLIBC_HAS_RPC__)
@@ -327,7 +328,7 @@ struct globals {
 	/* Used in next_line(), and as scratch read buffer */
 	char line[256];          /* _at least_ 256, see LINE_SIZE */
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 enum { LINE_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line) };
 #define rlim_ofile_cur  (G.rlim_ofile_cur )
 #define rlim_ofile      (G.rlim_ofile     )

networking/isrv_identd.c

@@ -18,6 +18,7 @@
 //usage:     "\n	STRING	Ident answer string (default: nobody)"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 #include "isrv.h"
 
@@ -29,6 +30,7 @@ typedef struct identd_buf_t {
 } identd_buf_t;
 
 #define        bogouser bb_common_bufsiz1
+#define sizeof_bogouser COMMON_BUFSIZE
 
 static int new_peer(isrv_state_t *state, int fd)
 {
@@ -118,7 +120,7 @@ int fakeidentd_main(int argc UNUSED_PARAM, char **argv)
 	opt = getopt32(argv, "fiwb:", &bind_address);
 	strcpy(bogouser, "nobody");
 	if (argv[optind])
-		strncpy(bogouser, argv[optind], sizeof(bogouser) - 1);
+		strncpy(bogouser, argv[optind], sizeof_bogouser - 1);
 
 	/* Daemonize if no -f and no -i and no -w */
 	if (!(opt & OPT_fiw))

networking/libiproute/ipaddress.c

@@ -13,6 +13,7 @@
 #include <net/if_arp.h>
 
 #include "ip_common.h"  /* #include "libbb.h" is inside */
+#include "common_bufsiz.h"
 #include "rt_names.h"
 #include "utils.h"
 
@@ -39,7 +40,7 @@ struct filter_t {
 } FIX_ALIASING;
 typedef struct filter_t filter_t;
 
-#define G_filter (*(filter_t*)&bb_common_bufsiz1)
+#define G_filter (*(filter_t*)bb_common_bufsiz1)
 
 
 static void print_link_flags(unsigned flags, unsigned mdown)

networking/libiproute/ipneigh.c

@@ -8,6 +8,7 @@
  */
 
 #include "ip_common.h"  /* #include "libbb.h" is inside */
+#include "common_bufsiz.h"
 #include "rt_names.h"
 #include "utils.h"
 #include <linux/neighbour.h>
@@ -40,7 +41,7 @@ struct filter_t {
 } FIX_ALIASING;
 typedef struct filter_t filter_t;
 
-#define G_filter (*(filter_t*)&bb_common_bufsiz1)
+#define G_filter (*(filter_t*)bb_common_bufsiz1)
 
 static int flush_update(void)
 {

networking/libiproute/iproute.c

@@ -11,6 +11,7 @@
  */
 
 #include "ip_common.h"  /* #include "libbb.h" is inside */
+#include "common_bufsiz.h"
 #include "rt_names.h"
 #include "utils.h"
 
@@ -43,7 +44,7 @@ struct filter_t {
 } FIX_ALIASING;
 typedef struct filter_t filter_t;
 
-#define G_filter (*(filter_t*)&bb_common_bufsiz1)
+#define G_filter (*(filter_t*)bb_common_bufsiz1)
 
 static int flush_update(void)
 {

networking/nc.c

@@ -8,6 +8,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 //config:config NC
 //config:	bool "nc"
@@ -252,7 +253,7 @@ int nc_main(int argc, char **argv)
 		fd = STDIN_FILENO;
 		while (1) {
 			if (FD_ISSET(fd, &testfds)) {
-				nread = safe_read(fd, iobuf, sizeof(iobuf));
+				nread = safe_read(fd, iobuf, COMMON_BUFSIZE);
 				if (fd == cfd) {
 					if (nread < 1)
 						exit(EXIT_SUCCESS);

networking/ping.c

@@ -28,6 +28,7 @@
 #include <net/if.h>
 #include <netinet/ip_icmp.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #ifdef __BIONIC__
 /* should be in netinet/ip_icmp.h */
@@ -186,7 +187,7 @@ struct globals {
 	char *hostname;
 	char packet[DEFDATALEN + MAXIPLEN + MAXICMPLEN];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 static void noresp(int ign UNUSED_PARAM)
@@ -378,7 +379,7 @@ struct globals {
 	} pingaddr;
 	unsigned char rcvd_tbl[MAX_DUP_CHK / 8];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define if_index     (G.if_index    )
 #define source_lsa   (G.source_lsa  )
 #define str_I        (G.str_I       )

networking/slattach.c

@@ -27,6 +27,7 @@
 //usage:     "\n	-F	Disable RTS/CTS flow control"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "libiproute/utils.h" /* invarg_1_to_2() */
 
 struct globals {
@@ -34,7 +35,7 @@ struct globals {
 	int saved_disc;
 	struct termios saved_state;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define handle       (G.handle      )
 #define saved_disc   (G.saved_disc  )
 #define saved_state  (G.saved_state )

networking/tc.c

@@ -29,6 +29,7 @@
 //usage:	"filter show [ dev STRING ] [ root | parent CLASSID ]"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #include "libiproute/utils.h"
 #include "libiproute/ip_common.h"
@@ -63,7 +64,7 @@ struct globals {
 	uint32_t filter_prio;
 	uint32_t filter_proto;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define filter_ifindex (G.filter_ifindex)
 #define filter_qdisc (G.filter_qdisc)
 #define filter_parent (G.filter_parent)

networking/tcpudp.c

@@ -67,6 +67,7 @@
 //usage:     "\n	-v		Verbose"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* Wants <limits.h> etc, thus included after libbb.h: */
 #ifdef __linux__
@@ -91,7 +92,7 @@ struct globals {
 	char **env_cur;
 	char *env_var[1]; /* actually bigger */
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define verbose      (G.verbose     )
 #define max_per_host (G.max_per_host)
 #define cur_per_host (G.cur_per_host)

networking/telnet.c

@@ -39,6 +39,7 @@
 #include <arpa/telnet.h>
 #include <netinet/in.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #ifdef __BIONIC__
 /* should be in arpa/telnet.h */
@@ -108,7 +109,7 @@ struct globals {
 	struct termios termios_def;
 	struct termios termios_raw;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 } while (0)

networking/telnetd.c

@@ -44,6 +44,7 @@
 #define DEBUG 0
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 
 #if DEBUG
@@ -82,7 +83,7 @@ struct globals {
 	const char *issuefile;
 	int maxfd;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.loginpath = "/bin/login"; \
 	G.issuefile = "/etc/issue.net"; \

networking/tftp.c

@@ -51,6 +51,7 @@
 //usage:     "\n	-l	Log to syslog (inetd mode requires this)"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 
 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
@@ -128,7 +129,7 @@ struct globals {
 	bb_progress_t pmt;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	BUILD_BUG_ON(sizeof(G) > COMMON_BUFSIZE); \
 } while (0)
@@ -757,7 +758,8 @@ int tftpd_main(int argc UNUSED_PARAM, char **argv)
 {
 	len_and_sockaddr *our_lsa;
 	len_and_sockaddr *peer_lsa;
-	char *local_file, *mode, *user_opt;
+	char *mode, *user_opt;
+	char *local_file = local_file;
 	const char *error_msg;
 	int opt, result, opcode;
 	IF_FEATURE_TFTP_BLOCKSIZE(int blksize = TFTP_BLKSIZE_DEFAULT;)

networking/udhcp/common.h

@@ -9,6 +9,7 @@
 #define UDHCP_COMMON_H 1
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <netinet/udp.h>
 #include <netinet/ip.h>
 

networking/udhcp/dhcpd.h

@@ -57,7 +57,7 @@ struct server_config_t {
 	struct static_lease *static_leases; /* List of ip/mac pairs to assign static leases */
 } FIX_ALIASING;
 
-#define server_config (*(struct server_config_t*)&bb_common_bufsiz1)
+#define server_config (*(struct server_config_t*)bb_common_bufsiz1)
 /* client_config sits in 2nd half of bb_common_bufsiz1 */
 
 #if ENABLE_FEATURE_UDHCP_PORT

networking/udhcp/dhcprelay.c

@@ -33,7 +33,7 @@ struct xid_item {
 	struct xid_item *next;
 } FIX_ALIASING;
 
-#define dhcprelay_xid_list (*(struct xid_item*)&bb_common_bufsiz1)
+#define dhcprelay_xid_list (*(struct xid_item*)bb_common_bufsiz1)
 
 static struct xid_item *xid_add(uint32_t xid, struct sockaddr_in *ip, int client)
 {

networking/udhcp/files.c

@@ -57,33 +57,35 @@ static int FAST_FUNC read_staticlease(const char *const_line, void *arg)
 struct config_keyword {
 	const char *keyword;
 	int (*handler)(const char *line, void *var) FAST_FUNC;
-	void *var;
+	unsigned ofs;
 	const char *def;
 };
 
+#define OFS(field) offsetof(struct server_config_t, field)
+
 static const struct config_keyword keywords[] = {
 	/* keyword        handler           variable address               default */
-	{"start"        , udhcp_str2nip   , &server_config.start_ip     , "192.168.0.20"},
+	{"start"        , udhcp_str2nip   , OFS(start_ip     ), "192.168.0.20"},
-	{"end"          , udhcp_str2nip   , &server_config.end_ip       , "192.168.0.254"},
+	{"end"          , udhcp_str2nip   , OFS(end_ip       ), "192.168.0.254"},
-	{"interface"    , read_str        , &server_config.interface    , "eth0"},
+	{"interface"    , read_str        , OFS(interface    ), "eth0"},
 	/* Avoid "max_leases value not sane" warning by setting default
 	 * to default_end_ip - default_start_ip + 1: */
-	{"max_leases"   , read_u32        , &server_config.max_leases   , "235"},
+	{"max_leases"   , read_u32        , OFS(max_leases   ), "235"},
-	{"auto_time"    , read_u32        , &server_config.auto_time    , "7200"},
+	{"auto_time"    , read_u32        , OFS(auto_time    ), "7200"},
-	{"decline_time" , read_u32        , &server_config.decline_time , "3600"},
+	{"decline_time" , read_u32        , OFS(decline_time ), "3600"},
-	{"conflict_time", read_u32        , &server_config.conflict_time, "3600"},
+	{"conflict_time", read_u32        , OFS(conflict_time), "3600"},
-	{"offer_time"   , read_u32        , &server_config.offer_time   , "60"},
+	{"offer_time"   , read_u32        , OFS(offer_time   ), "60"},
-	{"min_lease"    , read_u32        , &server_config.min_lease_sec, "60"},
+	{"min_lease"    , read_u32        , OFS(min_lease_sec), "60"},
-	{"lease_file"   , read_str        , &server_config.lease_file   , LEASES_FILE},
+	{"lease_file"   , read_str        , OFS(lease_file   ), LEASES_FILE},
-	{"pidfile"      , read_str        , &server_config.pidfile      , "/var/run/udhcpd.pid"},
+	{"pidfile"      , read_str        , OFS(pidfile      ), "/var/run/udhcpd.pid"},
-	{"siaddr"       , udhcp_str2nip   , &server_config.siaddr_nip   , "0.0.0.0"},
+	{"siaddr"       , udhcp_str2nip   , OFS(siaddr_nip   ), "0.0.0.0"},
 	/* keywords with no defaults must be last! */
-	{"option"       , udhcp_str2optset, &server_config.options      , ""},
+	{"option"       , udhcp_str2optset, OFS(options      ), ""},
-	{"opt"          , udhcp_str2optset, &server_config.options      , ""},
+	{"opt"          , udhcp_str2optset, OFS(options      ), ""},
-	{"notify_file"  , read_str        , &server_config.notify_file  , NULL},
+	{"notify_file"  , read_str        , OFS(notify_file  ), NULL},
-	{"sname"        , read_str        , &server_config.sname        , NULL},
+	{"sname"        , read_str        , OFS(sname        ), NULL},
-	{"boot_file"    , read_str        , &server_config.boot_file    , NULL},
+	{"boot_file"    , read_str        , OFS(boot_file    ), NULL},
-	{"static_lease" , read_staticlease, &server_config.static_leases, ""},
+	{"static_lease" , read_staticlease, OFS(static_leases), ""},
 };
 enum { KWS_WITH_DEFAULTS = ARRAY_SIZE(keywords) - 6 };
 
@@ -95,17 +97,17 @@ void FAST_FUNC read_config(const char *file)
 	char *token[2];
 
 	for (i = 0; i < KWS_WITH_DEFAULTS; i++)
-		keywords[i].handler(keywords[i].def, keywords[i].var);
+		keywords[i].handler(keywords[i].def, (char*)&server_config + keywords[i].ofs);
 
 	parser = config_open(file);
 	while (config_read(parser, token, 2, 2, "# \t", PARSE_NORMAL)) {
 		for (k = keywords, i = 0; i < ARRAY_SIZE(keywords); k++, i++) {
 			if (strcasecmp(token[0], k->keyword) == 0) {
-				if (!k->handler(token[1], k->var)) {
+				if (!k->handler(token[1], (char*)&server_config + k->ofs)) {
 					bb_error_msg("can't parse line %u in %s",
 							parser->lineno, file);
 					/* reset back to the default value */
-					k->handler(k->def, k->var);
+					k->handler(k->def, (char*)&server_config + k->ofs);
 				}
 				break;
 			}

networking/zcip.c

@@ -40,6 +40,7 @@
 //usage:     "\nexits only on I/O errors (link down etc)"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <netinet/ether.h>
 #include <net/if.h>
 #include <net/if_arp.h>
@@ -90,7 +91,7 @@ struct globals {
 	struct ether_addr our_ethaddr;
 	uint32_t localnet_ip;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 

procps/free.c

@@ -22,6 +22,7 @@
 //usage:       "Total:       386144       257128       129016\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #ifdef __linux__
 # include <sys/sysinfo.h>
 #endif
@@ -35,7 +36,7 @@ struct globals {
 # define G_unit_steps 10
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { } while (0)
 
 

procps/fuser.c

@@ -18,6 +18,7 @@
 //usage:     "\n	-SIGNAL	Signal to send (default: KILL)"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #define MAX_LINE 255
 
@@ -43,7 +44,7 @@ struct globals {
 	smallint kill_failed;
 	int killsig;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	G.mypid = getpid(); \
 	G.killsig = SIGKILL; \

procps/nmeter.c

@@ -53,6 +53,7 @@
 //  totalswap=134209536, freeswap=134209536, procs=157})
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 typedef unsigned long long ullong;
 
@@ -115,8 +116,8 @@ struct globals {
 	G.deltanz = G.delta = 1000000; \
 } while (0)
 
-// We depend on this being a char[], not char* - we take sizeof() of it
 #define        outbuf bb_common_bufsiz1
+#define sizeof_outbuf COMMON_BUFSIZE
 
 static inline void reset_outbuf(void)
 {
@@ -140,7 +141,7 @@ static void print_outbuf(void)
 static void put(const char *s)
 {
 	char *p = cur_outbuf;
-	int sz = outbuf + sizeof(outbuf) - p;
+	int sz = outbuf + sizeof_outbuf - p;
 	while (*s && --sz >= 0)
 		*p++ = *s++;
 	cur_outbuf = p;
@@ -148,7 +149,7 @@ static void put(const char *s)
 
 static void put_c(char c)
 {
-	if (cur_outbuf < outbuf + sizeof(outbuf))
+	if (cur_outbuf < outbuf + sizeof_outbuf)
 		*cur_outbuf++ = c;
 }
 

procps/ps.c

@@ -62,6 +62,7 @@
 //usage:       " 2990 andersen andersen R ps\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #ifdef __linux__
 # include <sys/sysinfo.h>
 #endif
@@ -144,7 +145,7 @@ struct globals {
 	unsigned long seconds_since_boot;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define out                (G.out               )
 #define out_cnt            (G.out_cnt           )
 #define print_header       (G.print_header      )

procps/top.c

@@ -105,6 +105,7 @@
 //config:	  Enable 's' in top (gives lots of memory info).
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 
 typedef struct top_status_t {
@@ -183,7 +184,7 @@ struct globals {
 	char line_buf[80];
 }; //FIX_ALIASING; - large code growth
 enum { LINE_BUF_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line_buf) };
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define top              (G.top               )
 #define ntop             (G.ntop              )
 #define sort_field       (G.sort_field        )

runit/runsv.c

@@ -45,6 +45,7 @@ ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <sys/file.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "runit_lib.h"
 
 #if ENABLE_MONOTONIC_SYSCALL
@@ -105,7 +106,7 @@ struct globals {
 	char *dir;
 	struct svdir svd[2];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define haslog       (G.haslog      )
 #define sigterm      (G.sigterm     )
 #define pidchanged   (G.pidchanged  )

runit/runsvdir.c

@@ -57,6 +57,7 @@ ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include <sys/file.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "runit_lib.h"
 
 #define MAXSERVICES 1000
@@ -84,7 +85,7 @@ struct globals {
 	unsigned stamplog;
 #endif
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define sv          (G.sv          )
 #define svdir       (G.svdir       )
 #define svnum       (G.svnum       )

runit/sv.c

@@ -189,6 +189,7 @@ Exit Codes
 
 #include <sys/file.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "runit_lib.h"
 
 struct globals {
@@ -199,7 +200,7 @@ struct globals {
 	uint64_t tstart, tnow;
 	svstatus_t svstatus;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define acts         (G.acts        )
 #define service      (G.service     )
 #define rc           (G.rc          )

runit/svlogd.c

@@ -155,6 +155,7 @@ log message, you can use a pattern like this instead
 
 #include <sys/file.h>
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "runit_lib.h"
 
 #define LESS(a,b) ((int)((unsigned)(b) - (unsigned)(a)) > 0)
@@ -1045,9 +1046,9 @@ int svlogd_main(int argc, char **argv)
 	}
 	if (opt & 2) if (!repl) repl = '_'; // -R
 	if (opt & 4) { // -l
-		linemax = xatou_range(l, 0, BUFSIZ-26);
+		linemax = xatou_range(l, 0, COMMON_BUFSIZE-26);
 		if (linemax == 0)
-			linemax = BUFSIZ-26;
+			linemax = COMMON_BUFSIZE-26;
 		if (linemax < 256)
 			linemax = 256;
 	}

scripts/generate_BUFSIZ.sh

@@ -0,0 +1,114 @@
+#!/bin/sh
+# Called from top-level directory a-la
+#
+# scripts/generate_BUFSIZ.sh include/common_bufsiz.h
+
+. ./.config || exit 1
+
+debug=false
+
+common_bufsiz_h=$1
+
+test x"$NM" = x"" && NM="${CONFIG_CROSS_COMPILER_PREFIX}nm"
+test x"$CC" = x"" && CC="${CONFIG_CROSS_COMPILER_PREFIX}gcc"
+
+regenerate() {
+	cat >"$1.$$"
+	test -f "$1" && diff "$1.$$" "$1" >/dev/null && rm "$1.$$" && return
+	mv "$1.$$" "$1"
+}
+
+generate_std_and_exit() {
+	$debug && echo "Default: bb_common_bufsiz1[] in bss"
+	{
+	echo "enum { COMMON_BUFSIZE = 1024 };"
+	echo "extern char bb_common_bufsiz1[];"
+	echo "#define setup_common_bufsiz() ((void)0)"
+	} | regenerate "$common_bufsiz_h"
+	exit 0
+}
+
+# User does not want any funky stuff?
+test x"$CONFIG_FEATURE_USE_BSS_TAIL" = x"y" || generate_std_and_exit
+
+test -f busybox_unstripped || {
+	# We did not try anything yet
+	$debug && echo "Will try to fit bb_common_bufsiz1[] into _end[]"
+	{
+	echo "enum { COMMON_BUFSIZE = 1024 };"
+	echo "extern char _end[]; /* linker-provided label */"
+	echo "#define bb_common_bufsiz1 _end"
+	echo "#define setup_common_bufsiz() ((void)0)"
+	} | regenerate "$common_bufsiz_h"
+	echo 1024 >"$common_bufsiz_h.BUFSIZE"
+	exit 0
+}
+
+# Get _end address
+END=`$NM busybox_unstripped | grep ' . _end$'| cut -d' ' -f1`
+test x"$END" = x"" && generate_std_and_exit
+$debug && echo "END:0x$END $((0x$END))"
+END=$((0x$END))
+
+# Get PAGE_SIZE
+echo "\
+#include <sys/user.h>
+#if defined(PAGE_SIZE) && PAGE_SIZE > 0
+char page_size[PAGE_SIZE];
+#else
+char page_size[1];
+#endif
+" >page_size_$$.c
+$CC -c "page_size_$$.c" || generate_std_and_exit
+PAGE_SIZE=`$NM --size-sort "page_size_$$.o" | cut -d' ' -f1`
+rm "page_size_$$.c" "page_size_$$.o"
+test x"$PAGE_SIZE" = x"" && generate_std_and_exit
+$debug && echo "PAGE_SIZE:0x$PAGE_SIZE $((0x$PAGE_SIZE))"
+PAGE_SIZE=$((0x$PAGE_SIZE))
+test $PAGE_SIZE -lt 1024 && generate_std_and_exit
+
+# How much space between _end[] and next page?
+PAGE_MASK=$((PAGE_SIZE-1))
+REM=$(( (-END) & PAGE_MASK ))
+$debug && echo "REM:$REM"
+
+if test $REM -lt 1024; then
+	# _end[] has no enough space for bb_common_bufsiz1[],
+	# users will need to malloc it.
+	{
+	echo "enum { COMMON_BUFSIZE = 1024 };"
+	echo "extern char *bb_common_bufsiz1;"
+	echo "void setup_common_bufsiz(void);"
+	} | regenerate "$common_bufsiz_h"
+	# Check that we aren't left with a buggy binary:
+	if test -f "$common_bufsiz_h.BUFSIZE"; then
+		rm "$common_bufsiz_h.BUFSIZE"
+		echo "Warning! Space in _end[] is too small ($REM bytes)!"
+		echo "Rerun make to build a binary which doesn't use it!"
+		exit 1
+	fi
+        exit 0
+fi
+
+# _end[] has REM bytes for bb_common_bufsiz1[]
+OLD=1024
+test -f "$common_bufsiz_h.BUFSIZE" && OLD=`cat "$common_bufsiz_h.BUFSIZE"`
+$debug && echo "OLD:$OLD"
+{
+echo "enum { COMMON_BUFSIZE = $REM };"
+echo "extern char _end[]; /* linker-provided label */"
+echo "#define bb_common_bufsiz1 _end"
+echo "#define setup_common_bufsiz() ((void)0)"
+} | regenerate "$common_bufsiz_h"
+echo $REM >"$common_bufsiz_h.BUFSIZE"
+
+# Check that code did not grow too much and thus _end[] did not shink:
+if test $OLD -gt $REM; then
+	echo "Warning! Space in _end[] has decreased from $OLD to $REM bytes!"
+	echo "Rerun make!"
+	exit 1
+fi
+
+if test $OLD != $REM; then
+	echo "Space in _end[] is $REM bytes. Rerun make to use larger COMMON_BUFSIZE."
+fi

selinux/setfiles.c

@@ -77,7 +77,7 @@ struct globals {
 	int nerr;
 	struct edir excludeArray[MAX_EXCLUDES];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 void BUG_setfiles_globals_too_big(void);
 #define INIT_G() do { \
 	if (sizeof(G) > COMMON_BUFSIZE) \

sysklogd/klogd.c

@@ -58,6 +58,7 @@
 //usage:     "\n	-n	Run in foreground"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <syslog.h>
 
 
@@ -146,8 +147,9 @@ static void klogd_close(void)
 #endif
 
 #define        log_buffer bb_common_bufsiz1
+#define sizeof_log_buffer COMMON_BUFSIZE
 enum {
-	KLOGD_LOGBUF_SIZE = sizeof(log_buffer),
+	KLOGD_LOGBUF_SIZE = sizeof_log_buffer,
 	OPT_LEVEL      = (1 << 0),
 	OPT_FOREGROUND = (1 << 1),
 };

sysklogd/logread.c

@@ -42,6 +42,7 @@
 //usage:     "\n	-F	Same as -f, but dump buffer first"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <sys/ipc.h>
 #include <sys/sem.h>
 #include <sys/shm.h>
@@ -67,7 +68,7 @@ struct globals {
 	struct sembuf SMrdn[2]; // {1, 0}, {0, +1, SEM_UNDO}
 	struct shbuf_ds *shbuf;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define SMrup (G.SMrup)
 #define SMrdn (G.SMrdn)
 #define shbuf (G.shbuf)

sysklogd/syslogd_and_logger.c

@@ -8,6 +8,7 @@
  */
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #define SYSLOG_NAMES
 #define SYSLOG_NAMES_CONST
 #include <syslog.h>

util-linux/mdev.c

@@ -97,6 +97,7 @@
 //usage:       "If /dev/mdev.log file exists, debug log will be appended to it."
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include "xregex.h"
 
 /* "mdev -s" scans /sys/class/xxx, looking for directories which have dev
@@ -285,7 +286,7 @@ struct globals {
 	struct rule cur_rule;
 	char timestr[sizeof("HH:MM:SS.123456")];
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define INIT_G() do { \
 	IF_NOT_FEATURE_MDEV_CONF(G.cur_rule.maj = -1;) \
 	IF_NOT_FEATURE_MDEV_CONF(G.cur_rule.mode = 0660;) \

util-linux/mkswap.c

@@ -13,6 +13,7 @@
 //usage:     "\n	-L LBL	Label"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if ENABLE_SELINUX
 static void mkswap_selinux_setcontext(int fd, const char *path)

util-linux/more.c

@@ -23,6 +23,7 @@
 //usage:       "$ dmesg | more\n"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 /* Support for FEATURE_USE_TERMIOS */
 

util-linux/mount.c

@@ -223,6 +223,7 @@
 #define BB_MS_INVERTED_VALUE (1u << 31)
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #if ENABLE_FEATURE_MOUNT_LABEL
 # include "volume_id.h"
 #else
@@ -447,7 +448,7 @@ struct globals {
 	char getmntent_buf[1];
 } FIX_ALIASING;
 enum { GETMNTENT_BUFSIZE = COMMON_BUFSIZE - offsetof(struct globals, getmntent_buf) };
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define nfs_mount_version (G.nfs_mount_version)
 #if ENABLE_FEATURE_MOUNT_VERBOSE
 #define verbose           (G.verbose          )

util-linux/script.c

@@ -23,6 +23,7 @@
 //usage:	)
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 int script_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int script_main(int argc UNUSED_PARAM, char **argv)
@@ -109,6 +110,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 	if (child_pid) {
 		/* parent */
 #define        buf bb_common_bufsiz1
+#define sizeof_buf COMMON_BUFSIZE
 		struct pollfd pfd[2];
 		int outfd, count, loop;
 		double oldtime = ENABLE_SCRIPTREPLAY ? time(NULL) : 0;
@@ -134,7 +136,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 			}
 			if (pfd[0].revents) {
 				errno = 0;
-				count = safe_read(pty, buf, sizeof(buf));
+				count = safe_read(pty, buf, sizeof_buf);
 				if (count <= 0 && errno != EAGAIN) {
 					/* err/eof from pty: exit */
 					goto restore;
@@ -157,7 +159,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 				}
 			}
 			if (pfd[1].revents) {
-				count = safe_read(STDIN_FILENO, buf, sizeof(buf));
+				count = safe_read(STDIN_FILENO, buf, sizeof_buf);
 				if (count <= 0) {
 					/* err/eof from stdin: don't read stdin anymore */
 					pfd[1].revents = 0;
@@ -176,7 +178,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
 		 * (util-linux's script doesn't do this. buggy :) */
 		loop = 999;
 		/* pty is in O_NONBLOCK mode, we exit as soon as buffer is empty */
-		while (--loop && (count = safe_read(pty, buf, sizeof(buf))) > 0) {
+		while (--loop && (count = safe_read(pty, buf, sizeof_buf)) > 0) {
 			full_write(STDOUT_FILENO, buf, count);
 			full_write(outfd, buf, count);
 		}

util-linux/swaponoff.c

@@ -28,6 +28,7 @@
 //usage:     "\n	-a	Stop swapping on all swap devices"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <mntent.h>
 #ifndef __BIONIC__
 # include <sys/swap.h>
@@ -62,7 +63,7 @@
 struct globals {
 	int flags;
 } FIX_ALIASING;
-#define G (*(struct globals*)&bb_common_bufsiz1)
+#define G (*(struct globals*)bb_common_bufsiz1)
 #define g_flags (G.flags)
 #define save_g_flags()    int save_g_flags = g_flags
 #define restore_g_flags() g_flags = save_g_flags

util-linux/uevent.c

@@ -25,11 +25,12 @@
 //usage:   "\n""	# uevent mdev & mdev -s"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 #include <linux/netlink.h>
 
 #define BUFFER_SIZE 16*1024
 
-#define env ((char **)&bb_common_bufsiz1)
+#define env ((char **)bb_common_bufsiz1)
 enum {
 	MAX_ENV = COMMON_BUFSIZE / sizeof(env[0]) - 1,
 };

util-linux/umount.c

@@ -34,6 +34,7 @@
 # define MNT_DETACH 0x00000002
 #endif
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if defined(__dietlibc__)
 // TODO: This does not belong here.
@@ -102,7 +103,7 @@ int umount_main(int argc UNUSED_PARAM, char **argv)
 		if (opt & OPT_ALL)
 			bb_error_msg_and_die("can't open '%s'", bb_path_mtab_file);
 	} else {
-		while (getmntent_r(fp, &me, bb_common_bufsiz1, sizeof(bb_common_bufsiz1))) {
+		while (getmntent_r(fp, &me, bb_common_bufsiz1, COMMON_BUFSIZE)) {
 			/* Match fstype if passed */
 			if (!match_fstype(&me, fstype))
 				continue;